What is diarrhea?

Going to the bathroom, having a bowel movement, pooping – no matter what you call it, stool is a regular part of your life. However, sometimes this process of getting waste out of your body changes. When you have loose or watery stool, it’s called diarrhea. This is a very common condition and usually resolves without intervention.

Diarrhea can happen for a wide variety of reasons and it usually goes away on its own in one to three days. When you have diarrhea, you may need to quickly run to the bathroom with urgency and this may happen more frequently than normal. You may also feel bloated, have lower abdominal cramping and sometimes experience nausea.

Although most cases of diarrhea are self-limited (happening for a fixed amount of time and steady level of severity), sometimes diarrhea can lead to serious complications. Diarrhea can cause dehydration (when your body loses large amounts of water), electrolyte imbalance (loss of sodium, potassium and magnesium that play a key role in vital bodily functions) and kidney failure (not enough blood/fluid is supplied to the kidneys). When you have diarrhea, you lose water and electrolytes along with stool. You need to drink plenty of fluids to replace what’s lost. Dehydration can become serious if it fails to resolve (get better), worsens and is not addressed adequately.

What’s the difference between normal diarrhea and severe diarrhea?

There are actually several different ways to classify diarrhea. These types of diarrhea include:

  • Acute diarrhea: The most common, acute diarrhea is loose watery diarrhea that lasts one to two days. This type doesn’t need treatment and it usually goes away after a few days.
  • Persistent diarrhea: This type of diarrhea generally persists for several weeks – two to four weeks
  • Chronic diarrhea: Diarrhea that lasts for more than four weeks or comes and goes regularly over a long period of time is called chronic diarrhea.

Who can get diarrhea?

Anyone can get diarrhea. It’s not uncommon for many people to have diarrhea several times a year. It’s very common and usually not a major concern for most people.

However, diarrhea can be serious in certain groups of people, including:

  • Young children.
  • Older adults (the elderly).
  • Those with medical conditions.

For each of these people, diarrhea can cause other health problems.

Can diarrhea harm your health?

In general, diarrhea is self-limited and goes away (resolves) without intervention. If your diarrhea fails to improve and resolve completely, you can be at risk of complications (dehydration, electrolyte imbalance, kidney failure and organ damage).

Call your healthcare provider if you have diarrhea that fails to get better or go away, or if you experience symptoms of dehydration. These symptoms can include:

  • Dark urine and small amounts of urine or loss of urine production.
  • Rapid heart rate.
  • Headaches.
  • Flushed, dry skin.
  • Irritability and confusion.
  • Light-headedness and dizziness.
  • Severe nausea and vomiting, the inability to tolerate or keep anything down by mouth.

What causes diarrhea?

The cause of most self-limited diarrhea is generally not identified. The most common cause of diarrhea is a virus that infects your bowel (“viral gastroenteritis”). The infection usually lasts a couple of days and is sometimes called “intestinal flu.”

Other possible causes of diarrhea can include:

  • Infection by bacteria.
  • Infections by other organisms and pre-formed toxins
  • Eating foods that upset the digestive system.
  • Allergies and intolerances to certain foods (Celiac disease or lactose intolerance).
  • Medications.
  • Radiation therapy.
  • Malabsorption of food (poor absorption).

Can antibiotics cause diarrhea?

Most antibiotics (clindamycin, erythromycins and broad spectrum antibiotics) can cause diarrhea. Antibiotics can change the balance of bacteria normally found in the intestines, allowing certain types of bacteria like C. difficile to thrive. When this happens, your colon can become overrun by bad (pathologic) bacteria that causes colitis (inflammation of your colon lining).

Antibiotic-associated diarrhea can begin any time while you’re taking the antibiotic or shortly thereafter. If you experience this side effect, call your healthcare provider to talk about the diarrhea and discuss the best option to relieve this side effect.

What are the symptoms of diarrhea?

The symptoms you can experience when you have diarrhea can vary depending on if it’s mild or severe and what the cause of the diarrhea happens to be. There’s a link between severe cases of diarrhea and a medical condition that needs to be treated.

When you have diarrhea, you may experience all of these symptoms or only a few. The main symptom of diarrhea is loose or watery stool.

Other symptoms of mild diarrhea can include:

  • Bloating or cramps in the abdomen.
  • A strong and urgent need to have a bowel movement.
  • Nausea (upset stomach).

If you have severe diarrhea, you may experience symptoms like:

  • Fever.
  • Weight loss.
  • Dehydration.
  • Severe pain.
  • Vomiting.
  • Blood.

Severe diarrhea can lead to significant complications. If you have these symptoms, call your healthcare provider and seek medical attention.

Last reviewed by a Cleveland Clinic medical professional on 04/13/2020.


  • US Department of Health and Human Services, National Institute of Diabetes and Digestive and Kidney Diseases. Diarrhea. Accessed 4/17/2020.
  • The Centers for Disease Control and Prevention. Diarrhea: Common Illness, Global Killer. Accessed 4/17/2020.
  • Merck Manual Professional Version. Diarrhea. Accessed 4/17/2020.

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